In the prior art, various types of "Telecomputing Systems" have been developed and commercially exploited for connecting remotely located computers together by using a communication network such as a PSTN (Public Switched Telephone Network). In Japan, for example, with enforcement of the telecommunications business code law in 1985, the so-called "Personal Computer Network" has flourished remarkably. A computer user, who enters into a contract with a service provider of a personal computer network, is allowed to access a given host (i.e., information server) of the provider.
A major trend of telecomputing in the recent years is to exploit the Internet. As well known in the art, the Internet is a generic name for networks around the whole world interconnected together based on the network "NSFnet", which was established in 1970's on an investment of the National Science Foundation (U.S.A.). While the Internet was originally intended to construct an international network for connecting universities and/or research institutions in 54 countries to facilitate exchange of information among them, as a respective server (mainly, UNIX workstation) installed at each of the universities and/or research institutions repeated interconnections independently, the network has grown into an enormous collection of networks covering the whole world with the present day Internet comprising several hundred thousands of servers scattered around the whole world. Remotely located server machines are interconnected in accordance with a protocol called "TCP/IP" (Transmission Control Protocol/Internet Protocol), whereby a data transfer or a communication on a BBS may be made between the connected computer systems.
While the prior (i.e., the originally intended) Internet was tinged with connections between computer systems in a UNIX environment, with its opening to the general public in 1994 and the resultant advent of providers (service providers), it has become widespread among general business organizations and/or individual users in an accelerative manner. For example, major service providers of personal computer networks in Japan (e.g., "PC-VAN", "NiftyServe" and the like) are now providing Internet connection services as well.
Since the Internet comprises a collection of networks, each having a different administrative/controlling organization with a different policy, there is no centralized organization to inclusively manage the Internet as a whole. In other words, each of the servers (e.g., database servers, file servers) scattered around the whole world is locally managed by a user in a network. Also, via a server connected to the Internet, each user of the Internet may act as an information provider, or may access any information on the Internet in a seamless manner. This is quite in contrast to the conventional "Personal Computer Network", which allows limited access to a given host only. Incidentally, as distinguished from "Internetworking" , which means to connect networks of certain business organizations together to construct a wide area network, the Internet is commonly denoted in English as the aforementioned proper noun ("the Internet").
As described, the substance of the Internet does not reside in a single computer system that is administered by a particular business organization or corporation. Rather, its substance resides in a collection of interconnected networks, each comprising a number of computer systems (server machines) for storing information.
In order to make use of the Internet, a user must connect his/her own computer (personal computer) to a subscriber server as its client. If the user is a researcher or a student, his/her computer may be connected as a client to a server machine owned by a research institute or a college to which the user belongs. On the other hand, in case of a general or regular user, he/she must enter into a contract with a commercial internet service provider (hereinafter called "an internet connection provider" or "service provider"). Some commercial internet services include "IBM internet connection service" of IBM Japan, Ltd., "BEKKOAME/INTERNET" of Bekkoame Internet, and the like.
While there are several types of contracts with a service provider, one of the services that is most easily available to an individual user is the so-called "dial-up IP" (IP standing for Internet Protocol). As well known, in the art, any computer system (server) connected to the Internet must acquire an identification number called an "IP address". In addition to its own IP address for connecting to the Internet, a service provider has a number of IP addresses, which are sequentially assigned to each of the contracted users who requests an Internet connection via a telephone line (i.e., dials-up), thereby to provide a window of the Internet. Also, most of the service providers have established connection points (i.e., access points) to be dialed-up by contracted users in all major cities of the country. Thus, a user may save his/her telephone charges by dialing up to the nearest access point. In other words, a user may use a telephone line and a modem for connecting his/her own PC to a server of a service provider as its client, thereby to establish a connection to the Internet. Further, through this server, the user may access data at another server (e.g., Web page) on the Internet.
On the other hand, a great variety of information equipment has been connected to the Internet. That is, when the Internet was beginning to spread, personal computers (PCs) installed at fixed sites such as offices, homes, eand the like were dial-up IP-connected using wires primarily. However, in these days, it is not unusual to establish a dial-up IP connection by using a PDA or PHS that has further improved portability/mobility over a notebook PC. Under a mobile environment, it is very rare to do a hard job using a word processing program (document editing) or a spreadsheet program. Rather, it is mostly sufficient to do a lighter job such as transmission of reports in the form of electronic mails. While a PDA (Personal Digital Assistant) or PHS (Personal Handyphone System) is merely capable of executing a simple application alone due to its limited input/output and processing capabilities, nevertheless it is capable of exchanging electronic mail and displaying data (e.g., text portions only). This is why, in a mobile environment, use of a PDA or a PHS, having a smaller size and a lighter weight, is desired over the use of a PC adhering to the full specifications.
More particularly, in the case of using a terminal such as a PHS that implements wireless communication functions, there is no need for a user to care about the position of a modular jack. That is, there is no need for a user of the Internet to stay at a particular site at all and, thus, the user may freely establish a dial-up IP connection under a mobile environment such as outdoors or any location to which the user moves. An advantage of connection to the Internet by means of a wireless communication terminal resides in the fact that its user is allowed to distribute electronic mail or to participate in BBS based on data/information acquired under a mobile environment, thereby to maintain immediateness or freshness of data. In other words, a wireless communication terminal of the portable type may become an information source having improved mobility. Further, a PHS is better than a cellular telephone in terms of lower manufacturing/operation costs, since a PHS has no limitation of frequency assignment or the like.
Even under a mobile environment, a user may be freely connected to the Internet for exchanging desired data or electronic mail. However, under a mobile environment, the nearest access point is not necessarily fixed. In the same manner as a user of a PHS or cellular telephone moves across cells, a mobile user is able to freely move across access points. As for a desktop PC installed at a particular site in a fixed manner, its nearest access point is also fixed and, thus, the previously setup access point may be used without any change. However, this is not true for a mobile user as set forth above.
There is no doubt that making a dial-up IP connection from the nearest access point requires the lowest cost. However, it will be extremely difficult or cumbersome for a user to store the nearest access point (telephone number) for each moving location respectively, or to change setup contents of a program.
It is, therefore, an object of this invention to provide an improved wireless information processing terminal that has additional information processing functions like PDA, and a method of controlling the same.
It is another object of this invention to provide an improved wireless information processing terminal that is connectable to a BBS or to an access point prepared by an internet provider for communicating data, and a method of controlling the same.
It is yet another object of this invention to provide an improved wireless information processing terminal that is connectable to an appropriate one of the access points prepared by an internet provider even under a mobile environment (i.e., at each moving location), and a method of controlling the same.